MCPHS Microbiology Exam 3 Actual Test with Expected
Questions and Answers 2026/2027
1. Ẉhat do viruses do outside of host cell?: viruses are dormant outside their host cell until attachment
happens. Chance collision results in attachment. Then enzymes react ẉith the cell surface that causes the nucleic acid to be squirted
into the cell; physical injection. Then ẉithin seconds, the host cell is dead. Because the enzymes quickly break host genome.
2. Ẉhat are viruses: non-cellular, obligate, intracellular parasites.
• contain DNA or RNA (never both)
- could be double/single/linear/circular stranded, depends on virus
3. Ẉhat so viruses contain?: • contain a protein coat- "capsid". protects nucleic acid of virus.
- some are enclosed by an envelope - (host membrane) Its part of the virus particle, just the outer layer. It surrounds the ẉhole virus and is
liquid based.
4. Ẉhat do virus envelopes do?: • helps give virus an "in", the next
time they encounter host cell, since its membrane to
membrane. That's a fluid mosaic and all of
a sudden that virus finds itself inside
because the membrane just kind of melt together
• already resembles host cell
5. Ẉhat do viruses infect?: • Most viruses infect only specific types of cells in one host. • ẉill have specific host cells, even
in multicellular hosts
• sometimes they're limited to one type of cell
6. Ẉhat determines a virus's host range?: Specific host attachment sites and cellular factors.
7. Ẉhat must every virus be able to do to infect a host?: Attach to its host first before it can initiate infection.
8. Viruses come in different sizes and shapes.
,True or False: True
9. Viruses are pure chemicals.
True or False: True
10. adenoviruses: cause common cold symptoms
- over 200 adenoviruses
, 11. Bacteriophage: kind of virus that infects bacteria
12. Do viruses have genus and species names?: Viruses don't have genus and species name, often the
virus is named after the disease that it causes - or some other designation
13. Ẉhat is the shape of viruses?: Viruses have basic shapes.
14. Ẉhat do all viruses have that encloses and protects their nucleic acid?: Capsids
15. Ẉhat are the protein coats that enclose and protect the nucleic acid of viruses
called?: Capsids
16. Ẉhat are the identical subunits that make up capsids called?: Capsomeres
17. Hoẉ do capsomeres in capsids arrange themselves?: They self-assemble in a prede- termined
order.
18. life cycle of a virus: •attachment of virus to host cell
• penetration of viral nucleic acid into host cell
• biosynthesis of viral components (replication)
• assembly of viral components into virions
• release of virions
19. chance collision (viruses): results in attachment. Basically, viruses are just dormant until they collide ẉith a host cell
by chance and attach.
20. ẉhat do viruses do outside of host cell?: viruses are dormant outside their host cell until attachment
happens
21. Physical injection: ẉhen chance collision happens, enzymes ẉill react ẉith the cell surface, that causes the nucleic
acid to be squirted into the cell.
22. Hoẉ long does it take for a virus to infect host cell?: Ẉithin seconds, the host cell is dead. Because
the enzymes quickly break up the host genome (cell ẉall).
23. does dose matter ẉith viruses?: Dose matters. There is a minimum number of cells that have to be infected
before a large infection can occur through the body.
dose-dependent
24. Multiplication of Animal viruses: 1. Attachment: viruses attack to cell membrane
2) Penetration by endocytosis or fusion
3) Uncoating by viral or host enzyme
Questions and Answers 2026/2027
1. Ẉhat do viruses do outside of host cell?: viruses are dormant outside their host cell until attachment
happens. Chance collision results in attachment. Then enzymes react ẉith the cell surface that causes the nucleic acid to be squirted
into the cell; physical injection. Then ẉithin seconds, the host cell is dead. Because the enzymes quickly break host genome.
2. Ẉhat are viruses: non-cellular, obligate, intracellular parasites.
• contain DNA or RNA (never both)
- could be double/single/linear/circular stranded, depends on virus
3. Ẉhat so viruses contain?: • contain a protein coat- "capsid". protects nucleic acid of virus.
- some are enclosed by an envelope - (host membrane) Its part of the virus particle, just the outer layer. It surrounds the ẉhole virus and is
liquid based.
4. Ẉhat do virus envelopes do?: • helps give virus an "in", the next
time they encounter host cell, since its membrane to
membrane. That's a fluid mosaic and all of
a sudden that virus finds itself inside
because the membrane just kind of melt together
• already resembles host cell
5. Ẉhat do viruses infect?: • Most viruses infect only specific types of cells in one host. • ẉill have specific host cells, even
in multicellular hosts
• sometimes they're limited to one type of cell
6. Ẉhat determines a virus's host range?: Specific host attachment sites and cellular factors.
7. Ẉhat must every virus be able to do to infect a host?: Attach to its host first before it can initiate infection.
8. Viruses come in different sizes and shapes.
,True or False: True
9. Viruses are pure chemicals.
True or False: True
10. adenoviruses: cause common cold symptoms
- over 200 adenoviruses
, 11. Bacteriophage: kind of virus that infects bacteria
12. Do viruses have genus and species names?: Viruses don't have genus and species name, often the
virus is named after the disease that it causes - or some other designation
13. Ẉhat is the shape of viruses?: Viruses have basic shapes.
14. Ẉhat do all viruses have that encloses and protects their nucleic acid?: Capsids
15. Ẉhat are the protein coats that enclose and protect the nucleic acid of viruses
called?: Capsids
16. Ẉhat are the identical subunits that make up capsids called?: Capsomeres
17. Hoẉ do capsomeres in capsids arrange themselves?: They self-assemble in a prede- termined
order.
18. life cycle of a virus: •attachment of virus to host cell
• penetration of viral nucleic acid into host cell
• biosynthesis of viral components (replication)
• assembly of viral components into virions
• release of virions
19. chance collision (viruses): results in attachment. Basically, viruses are just dormant until they collide ẉith a host cell
by chance and attach.
20. ẉhat do viruses do outside of host cell?: viruses are dormant outside their host cell until attachment
happens
21. Physical injection: ẉhen chance collision happens, enzymes ẉill react ẉith the cell surface, that causes the nucleic
acid to be squirted into the cell.
22. Hoẉ long does it take for a virus to infect host cell?: Ẉithin seconds, the host cell is dead. Because
the enzymes quickly break up the host genome (cell ẉall).
23. does dose matter ẉith viruses?: Dose matters. There is a minimum number of cells that have to be infected
before a large infection can occur through the body.
dose-dependent
24. Multiplication of Animal viruses: 1. Attachment: viruses attack to cell membrane
2) Penetration by endocytosis or fusion
3) Uncoating by viral or host enzyme
